Hydraulic power system



Dex; 30, 1969 R R. FORKNER HYDRAULIC POWER SYSTEM Fild June 24, 1968 United States Patent O 3,487,431 HYDRAULIC POWER SYSTEM Robert R. Forkner, Yorba Linda, Calif., asslgnor, by mesne assignments, to Whittaker Corporation, Los Angeles, Calif., a corporation of California Filed June 24, 1968, Ser. No. 739,551 Int. Cl. F04b l7/00, 39/06; F15b 15/18 U.S. Cl. 103-57 3 Claims ABSTRACT OF THE DISCLOSURE An hydraulic power system is provided which is capable of circulating hydraulic fluid under pressure for the hydraulic control of a wide variety of instrumentalities. The hydraulic power system of the invention incorporates an internal fluid cooling system so that the need for a separate external cooler for the circulated hydraulic fluid is obviated.

BACKGROUND OF THE INVENTION Hydraulic power systems in the prior art include a pump which is driven by an electric motor. The pump forces hydraulic fluid under pressure from a reservoir to the instrumentality which is to be hydraulically controlled by the system. The hydraulic uid is then returned to the reservoir. Since the hydraulic fluid undergoes a heating eiect as it is circulated through the controlled instrumentality, a separate cooler is provided in the return line of the prior art systems, so as to maintain the uid within an acceptable temperature range.

The hydraulic power system of the present invention is constructed, as will be described, to include an internal air cooled reservoir. In this manner, the hydraulic uid in the system is maintained within the desired temperature range, and this is achieved without the need for a separate external cooler.

BRIEF DESCRIPTION OF THE DRAWING FIGURE 1 is a side elevational view showing one embodiment of the improved hydraulic power system of the present invention, and particularly illustrating the internal components which make up the system;

FIGURE 2 is an end section taken on the line 2-2 of FIGURE 1, and showing other components of the system; and

FIGURE 3 is a perspective view of a unit incorporating the improved hydraulic power system of the invention.

DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENT The hydraulic power system shown in the drawing includes, for example, a reservoir which contains a quantity of hydraulic fluid. A pump is mounted on the reservoir, and the intake port of the pump is coupled to an intake line 22 which extends down into the reservoir. The pump draws fluid out of the reservoir through a lilter 24 at the end of the line 22, and through the intake of the pump.

The pump then forces the fluid under pressure from its outlet pressure port, to which is coupled an outlet line 2'6. The pressurized fluid from the pump 20 is pumped through the outlet line 26 and through a lter 28 to the instrumentality which is to be controlled by the system. The fluid is circulated through the controlled instrumentality and returned to the reservoir 10 through an appropriate return line, and into a return port 3Q.

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The pump 20 is driven by an electric motor 32 which, likewise, is mounted on the reservoir 10, and which is mechanically coupled to the pump. The unit also includes a hood 34 which is itted down over the motor 32 and pump 20, and which extends over the sides of the reservoir 10. The hood 34 defines air ducts around the reservoir 10, as -best shown in FIGURE 2. A fan 40 is mechanically coupled to the motor 32 to be driven thereby, the fan likewise being positioned Within the compartment defined between the hood 34 and the reservoir 10. The fan serves to draw cooling air up through the ducts formed by the hood 34 around the reservoir 10, and to expel the air out through a louvered opening 42 in the rear side of the hood.

As shown in FIGURE 3, an appropriate pressure gauge 50, as well as a level gauge and thermometer 52, and a drain 54 may be provided in the unit. These instruments and drain, as well as the filter 28, are mounted on a front panel 60, and the hood 34 has a sliding lit over the reservoir 10, so as to provide easy access for the components mounted on the reservoir and supported Within the hood.

The hydraulic power system described above serves to pump pressurized hydraulic fluid through the filter 28 to the controlled instrumentality, with the luid being returned to the reservoir of the unit in a heated state through the return line and return port 30. However, due to the fact that an air cooling system is provided for the reservoir, as described above, the temperature of the returned fluid is rapidly cooled to a desired temperature level. This cooling of the fluid in the reservoir is achieved internally in a simple and inexpensive manner, and the need for a separate cooler, as is used in the prior art systems, is obviated.

It will be appreciated that although a particular embodiment of the invention has been described and illustrated, modifications may be made. It is intended to cover al1 such modifications in the following claims.

What is claimed is:

1. An hydraulic power system including:

a reservoir for containing a quantity of hydraulic fluid;

a pump mounted on said reservoir and including an intake port and a pressure port;

an intake line coupled to said intake port of said pump and extending into said reservoir;

a pressure line coupled to said pressure port of said Pump;

a return line extending into said reservoir;

a drive motor for said pump mechanically coupled to said pump;

air ducts extending around said reservoir; and

a fan for circulating cooling air through said ducts to cool the fluid in said reservoir.

2. The system defined in claim 1, in which said fan is mechanically coupled to said drive motor to be driven thereby.

3. The system delined in claim 1, and which includes a hood surrounding said fan and said motor and said pump, said hood defining said air ducts for said reservoir.

References Cited UNITED STATES PATENTS 7/ 1927 Oliver 230-211 XR 8/1964 Lever 230-211 ROBERT M. WALKER, Primary Examiner 

